Boring-tool



WHOM 05A. SIMMONS.

BORING TOOL.

110.374. 132. Patented Dec. 6, 1887.

INVENTOR:

By Atty,

N. Firing Plwto-LilhugI-apher, Wnshinghm. ac

iUNITED STATES PATENT OFFICE.

CLARENCE A. SIMMONS, OF NORlVOOD, MASSACHUSETTS.

BORING-TOOL.

SPECIPICATIONforming part of Letters Patent No. 374,432, dated December6, 1887.

(No model.)

To all whom. it may concern.-

Be it known that 1', CLARENCE A. SIMMONS, a citizen of the UnitedStates, residing at Non wood, in the county of Norfolk and State ofMassachusetts, have invented certain new and useful Improvements inBoring-Tools,ofwhich the following is a specification.

This invention relates to certain improvements in angers or boring-toolswhich are adapted for boring in different woods,in metal, or in stone.

The object of the invention is to provide an anger or boring-tool whichshall be strong and durable, and which will freely discharge thematerial bored out, and which willbe less liable to run or deviate fromthe right line when used with the grain of the wood ordiagonally to it,and one, also, which will last much longer and which can always be keptsharp by grinding the cutting-edges. I attain this ob ject by means ofthe device illustrated in the accompanying drawings, forming a part ofthis specification, and in which- Figure I is an elevation of thisimproved auger provided with a central pin or worm, and with scoringcutters or spurs which especially adapt it for use in boring wood. Fig.II is a plan of the cutting end of this improved auger. Fig. III is anelevation of a portion of this improved anger of the form illustrated inFig. I, but at a quarter-turn from the position shown therein. Fig. IVrepresents cross-sections of the anger on the line iv to of Fig. I,according to the construction which is adopted. Fig. V illustratesdifferent forms of transverse sections taken on the line 7; '0 of Fig.I, according to the constrnction adopted for the lower section of theauger. Fig. VI is a diagram illustrating one of the clearance-groovesdeveloped in a plane,

instead of being wound helically around the auger. Fig. VII shows thelowerend of this improved auger provided with an ordinary drill-point,the worm and spurs being omitted.

The same numerals of reference have been applied to corresponding partsin the several figures of the drawings.

The shaft of this improved auger is of cylindrical or any other desiredconstruction,and is preferably provided at its upper end with anordinary angular tapered shank adapted to fit the socket ofa brace orbit stock; or it may be provided with a handle or other means forturning it in the direction desired.

The twisted blade of this improved auger comprises an upper portion, 1,having a regular or uniform twist, and a lower portion, 2, having anirregular twist,0r a twist ofgreater pitch than that of the upperportion. The cross-section of the upper portion or regular twist is ofany suitable form, size, or thick ness, several forms being illustratedin Fig. IV. The blade of the anger at the irregular twist is thicker atthe periphery than at the center, and may be of diiferent forms, twovariations being illustrated in Fig. V.

The anger is provided with two deliverygrooves, 3 4, which graduallywiden from the cutters upward, preferably through the irregular to theregular twist, in which they are of uniform width. The delivery-groovesmay be of uniform width through the lower section of the auger, ifdesired. It will be obvious that the steep pitch of the grooves near thecutters will cause the chips to be lifted rapidly away from said cuttersinto the grooves of regular pitch and of easier grade above,througl1which they will be conveyed upward and discharged at the mouth of thehole being bored as rapidly as may be necessary; and when thedeliverygrooves are gradually widened from the cutters upward, asstated, clogging is prevented and the anger or drill does better work.The blade of the anger at the irregular twist, being thicker at theperiphery than at the center, presents a greater bearing-surface to thegrain of the wood, thus keeping it true and steady to its course,especially when used with the grain of the wood or diagonally to it. Thepeculiar construction of the twisted blade of this improved auger and ofthe grooves formed therein thus adapt it to boring in wood, metal, orstone with great rapidity and facility.

The floor lips or cutters 5 and 6 may be either horizontal or inclined;but I prefer to make them inclined toward the sides. They presentslightly concave or convex or straight cutting-edges to the work, asmaybe desired, and extend tangentially from the root of the worm 8 tothe circumference of the auger.

The cutters are preferably beveled or cut away in the rear of thecutting-edge to render the latter sharp.

On the end of the auger and upon the edges of the blades, slightly inthe rear of the cutters, are formed downwardly-projecting spurs 7, whichserve the ordinary function of circularly incisingthe material beingbored. I may, however, if desired, dispense with either of the spurs 7or the worm 8, or both; but when the worm, or both the worm and spurs,are dispensed with the cutting-edges should be shaped, by grinding orotherwise, as shown in Fig. VII.

An auger constructed as hereinbefore described possesses the advantagesof rapidly clearing the hole being bored of chips, of operating eitheracross, diagonally to, orin line with the grain of the wood or throughknots or other obstacles therein, and of being readily ground whendulled bylong continued use.

If by long use the auger or drill becomes smaller in circumference atits lower end than at the regular twist, it can be enlarged by swagingit at the center of the deliverygrooves 3 and 4. t

The lower section of this improved auger can be made of any lengthdesired, and when it is constructed without a worm or spur, as shown inFig. VII, may be ground and used as long as this portion of the augerwill last.

I claim as my invention- 1. A boring-tool comprising a twisted blade andcutters at the lower end thereof, said blade in its lower part beingthicker at its periphery than at its center, and having two spiraldelivery-grooves the pitch of which is greater at the lower than at theupper part of the blade, substantially as described.

2. A boring-tool comprising atwisted blade and cutters at the lower endthereof, said blade in its lower part being thicker at its peripherythan at its center, the thickness gradually increasing toward thecutters, and having two spiral delivery-grooves, the pitch of saidgrooves increasing and the width thereof decreasing toward the cutters,substantially as described.

3. A boring-tool comprising atwisted blade and a worm and cutters at thelower end of the blade, said cutters being provided with spurs slightlyin the rear of their cuttingfaees, and said blade in its lower partbeing thicker at its periphery than at its center,and having two spiraldelivery-grooves the pitch of which is greater at the lower than at theupper part of the blade, substantially as described.

4. A boring-tool having a spiral delivery- OL ARENCE A. S [M MONS.

NVitnesses:

EDWARD F. STEVENS, J AMES SIMMONS.

